Restarting your Windows device might help the resolution apply to your device faster. Please note that it might take up to 24 hours for the resolution to propagate automatically to consumer devices and non-managed business devices. Note: This KIR will prevent the issue on Windows devices which have not installed KB5015878 but will have no effect on devices already affected by this known issue. Resolution: This issue is resolved using Known Issue Rollback (KIR). Note: The article uses the microphone as an example, but you will need to do the steps for any affected audio device. If your device's audio is still not working as expected, follow the instructions in Disable Audio Enhancements.The Get Help dialog window should open, and you will need to select yes to open the troubleshooter. You can launch the troubleshooter from Fix sound or audio problems in Windows by selecting the Open Get Help button in the article. The Windows audio or sound troubleshooter might be able to resolve the issue for you.
If you have already installed the update and are experiencing issues with audio on all apps, you can try the following to mitigate the issue:
Caching the MMDevice ID is not recommended and might require reinstallation of the affected app or contacting support for the developer of the app for how to resolve the issue when audio endpoints are reinitialized and have new MMDevice IDs. If the device settings within the app are as expected, the apps might be caching the Windows Multimedia Device (MMDevice) ID.Audio endpoints might be reinitialized after KB5015878 is installed and some apps might set the audio devices for microphone and speakers to default. Verify that the audio devices set within those apps are the expected devices.If only certain apps are impacted, you can try the following to mitigate the issue: If you are using any advanced audio applications such as Open Broadcaster Software (OBS), it is recommended that you backup all your settings before installing the update.
If there are updated drivers available on Windows Update or from your Windows device manufacturer's (OEM) webpage, installing them might prevent this issue.